Charlotte, who welcomed her first son Raphäel in December 2013, looked as chic as ever in a sequined pink and black dress. The equestrian star's partner
Gad Elmaleh, who is father to one-year-old Raphäel, was unable to attend.

For the event, an equally dazzling 29-year-old Beatrice sported a silver gown and wore her golden locks in lose waves, displaying a stunning diamond necklace and matching earrings. The Newsweek
journalist and her future husband then hit the dancefloor, showing off their moves with 28-year-old Charlotte as singerLily Allen performed.

Chanel maestro
Karl Lagerfeld made his way to Monaco for the affair that supports the late Princess Grace Foundation. He wore a black suit and his trademark sunglasses.

Charlotte and Beatrice let their hair down on the dance floor with singer Lily Allen Photo: Getty Images

Pierre's older brother
Andrea Casiraghi and his wife Tatiana Santo Domingo also missed the ball as they are awaiting the imminent arrival of their second child. It had been speculated that heavily pregnant Tatiana would not make the party as our sister publication in Spain, HOLA! reported on Friday that a source said the 31-year-old will give birth in the next "five or 10 days." Tatiana, who wed her long-term love Andrea in August 2014 after seven years of dating, is already mother to two-year-old Sascha.